Circulatory system

• The heart is a muscular organ that pumps blood around the body.
• The differences between a vein and artery is that a vein pumps blood to the heart and the artery pumps blood away from the heart. The artery contains more oxygenated red blood cells. The red blood cells contain haemoglobin while the white blood cells do not.
• High blood pressure can cause damage to organs such as kidneys, brain and eyes. This can lead to serious health problems like strokes or heart attacks.
• Blood pressure is the force of blood pushing against the walls of your arteries as it moves through them. It's measured using two numbers - systolic (the higher number) and diastolic (the lower number). Systolic is when the heart beats and pumping blood out into the arteries. Diastolic is when the heart relaxes and fills up again with blood.
• Different types of white blood cells: granulocytes (neutrophils, eosinophils, and basophils), monocytes, and lymphocytes
• Neutrophils are the most common type of WBC. They destroy bacteria by engulfing them and releasing enzymes inside the cell.
• Monocytes become macrophages which phagocytize dead cells and foreign substances.
• Basophils release histamine during an allergic reaction.
• Eosinophils defend against parasites and allergens.
• Basophils release histamine which causes inflammation and swelling at an infection site
• Eosinophils defend against parasites and allergens
• Kidneys

  A pair of bean-shaped organs located in the lower back, below the ribcage. Primary function: filter waste and excess fluids from the blood.
• Liver


  A single, large organ located in the upper right part of the abdomen, just below the diaphragm. Primary function: detoxify harmful substances in the body, metabolize nutrients, and store vitamins and minerals.
• Phagocytizing dead cells


  The process by which macrophages engulf and digest dead cells and debris in the body
• Presenting antigens


  The process by which macrophages display antigens on their surface to alert T-cells to the presence of a pathogen